Strip forming mold



Dec. 25, 1951 A, H, NARROW 2,579,691

STRIP FORMING MOLD Filed DeC. 5, 1949 (Ittomeg Patented Dec. 25, A1951UNITED STATES PATENT OFFICE STRIP FORMING MOLD Anton H. Narrow, Memphis,Tenn.

Application December 5, 1949, Serial No..13'1,14

(Cl. 22l36) Claims. l

This invention relates to certain new and use ful improvements in a moldor die for forming a continuous strip or bar `of soft metal, partcularlyof type metal and similar alloys, which mold may be used in connectionwith an extrusion process or may be used in a process in which the castmetal may be drawn or pulled from the die as it emerges, or suchextrusion or pulling action may be combined.

Specifically the present invention relates 4to new and usefulimprovements in the spacing members, conventionally heretofore employedin connection with similar dies or molds and in a new entrancearrangement into the channel forming the interior of the mold.

Heretofore `molds of the same general character have been employed inthe formation of strips of the character mentioned, particularly for usein the printing art inthe formation of rules, lines and the like, andthe strips thus formed have essentially constituted 'ribbon-like. fiat,continuous members formed by the solidification of the molten type-metalor other alloy within the mold, the finished strip being withdrawn orextruded from the exit end of the mold.

In the preparation of such strips for use as rules in printing by whicha thin straight line is imprinted upon a page as desired, it has beencustomary to form along one edge of the strip a bevel or shaped edgewith the apex of the bevel forming the portion used to imprint the lineupon the page. It has been found, due to the properties of the alloyscommonly used in type-metal, that, unlike other metals, there is anexpansion of such type-metal alloys upon cooling from molten state to asolid state with the result that it has heretofore been customary toprovide a microscopic divergence between the upper and lower' edges ofthe channel of the previous molds to compensate for such expansion andto permit ease of operation in the continuous production of the desiredstrips. It is frequently found that the strips, formed in molds ofconventional type having such diverging upper and lower edges, areimproperly burnished and the printing edge of the prepared strip hasfrequently been found to be pitted and otherwise defective in a mannerundesirable 'in connection with the printing art.

The principal object of this invention is to provide a mold for formingstrips of type-metal which includes means for burnishing the printingedgeof the formed strip to eliminate therefrom any undesired pits andother irregularities.

A further object of the invention is to improve the arrangement of theentrance to such molds through which molten metal is introduced into themold so as to insure the introduction of the molten metal to theprinting-"edgeeforming portion of said mold.

A further object of the invention is to provide a mold for formingstrips which includes opposite side members forming sides of the moldchannel and upper and lower longitudinal spacers spacing the sidemembers apart and constituting the upper and lower edges of the moldchannel, 'in which one of the spacers is scarred 'for the formation of afine line printingsurface along one edge of the formed strip and thescarfed spacer adjacent the exit end of the channel converges toward theopposite spacer to reduce the width of the channel, the cast strip beingdrawn beyond the reduced width portion.

A further object of the invention is to provide such a mold in which theaforesaid scarfed spacer and converging `end section is disposed as theupper spacer of the mold.

A further objectvof the invention is to provide such a mold in which thescaried spacer is converged toward the opposite spacer along a gradualarc.

A further object of the invention is to provide a mold for formingstrips in which the entrance to the mold channel is restricted Aby ablock member, which block member lies intermediate Athe upper and lowerspacers and is spaced `from both oation upon reference to theaccompanying drawings, in which:

Fig. 1 is a side elevational view of the mold of the present inventionwith a strip shown emerging therefrom.

Fig. 2 is a sectional elevational View taken on the line II-II of Fig.1.

Fig. 3 is a sectional view taken on the line III-III of Fig. 2.

Fig. 4 is a fragmentary view similar to Fig. 3 on a greatly enlargedscale illustrating a preferred embodiment of the converging longitudinalspacer of the present invention; and

Fig. 5 is a view similar to Fig. 4 of a variation in the embodiment ofthe converging spacer.

Referring now to the drawings in which the various parts 'are indicated'by numerals, the

mold of the present invention consists of a pair of side members IIwhich are substantially identical, but which, as indicated in Fig. 2,may be of differing thicknesses, and to each of which is preferablyaffixed a side channel face or liner I3, liners I3 being preferablyseparate elements substantially identical with those shown in myco-pending application, Serial No. 115,541, although it `will beunderstood that insofar as the present invention is concerned it may beused equally as well in connection with those molds in which the innerliners I3 are integral with side members II and are employed as thesides of the mold channel. Interposed between the channel liners I3 andbetweenY the side members II are longitudinal upper and lower spacersI5, IE which are preferably of substantially rectangular shape, extendfrom end` to end of the mold, maintain spacing between the-,channelliners I3 and` respectively form the upper and lower edges of the moldchannel. It will be seen that channel liners I3 and spacers I5, I6 forma channel extending from end to end of the mold and terminating in anexit opening I1.

Preferably lower spacer I6 is provided with a flat straight upper edgeI8 `so as to form a relatively straight edge along the lower edge of astrip formed in the mold'. The lower edge l5 of upper spacer I ispreferably scarfed as at ISA to form a beveled elongated recess alongthe lower edge I9 which is effective to impose a sharpened printing edge2D on the strip 2I formed in the mold and to thereby provide for theprinting of a line line when strip 2l is so employed.

Preferably, as is conventional, lower edge I9 of upper spacer I5diver-ges minutely away from upper edge I8 of lower spacer I5 through amajority of the length of the respective liners. Adjacent the exit endI1 of the channel formed in the mold, lower edge- I9 of upper spacer i5is provided with a curved portion 22 which converges toward upper edgeAI8 4of lower spacer i@ so as to restrict exit opening I1, with themaximum' restriction being preferably formed closely adjacent opening I1as at 23.

It will be observed that in the drawings illustrating the presentinvention the curvature of curved end portion 22 of lower edge i3 ofspacer I5 is preferably a microscopic curvature', being substantiallyexaggerated in the drawings for the purpose of illustration. It will,however, be understood that although the microscopic character of thiscurvature is preferred it is not intended that the present invention belimited to such microscopic dimension. It has been found that thespacing between the respective edges I9, I8 of upper and lower spacersI5, le is preferably narrowed from the point of beginning of curvedportion 22 to the point 23 of maximum curvature in a range lying between.003

passageway 21 intimately associated with the scarfedV edge of' spacerI5, so that the upper edge of passageway 21 is longitudinally alinedwith the scarfed edge, and the lower edge of the block is also spacedabove upper edge I8 of spacer I6 to form a conventional lower inletpassageway 29. Block 25 is preferably maintained in position by suitabledowel pins 3| which extend through the block and maintain it inalinement. Preferably additional dowels 33 are provided to maintain thealinement of spacers I5, I5, and the entire device is preferablydetachably secured by suitable screws 35.

in the use of the device it is assembled as described and moltentype-metal is introduced as through a suitable spout 31 into theentrance endof the device. Preferably the molten metal is supplied tospout 31 by a suitable pressure device, not shown, so that it isintroduced through passages 21, 29 into the interior of the mold under asuitable pressure.

VThe molten metal flowing through upper passageway 21 isv enabled to oWdirectly into the scarng I9A of lower edge I9 of upper spacer I5 and isenabled to quickly and properly ll the beveled scarring so as to beginthe proper formation of printing edge 2G without depending upon theinward flow of molten metal introduced through passage 29. In thismanner introduction of the molten metal into the scarfed edge-formingportion is insured. As the introduction of molten metal through spout 31is continued the metal is advanced along the interior of the channelbetween liners i3 and upper and lower spacers I5, I5. The metalcontinues in a molten state for a substantial distance in its passagethrough the mold and begins to solidify, preferably beyond the mid pointof movement toward discharge end I1 and emerges from the discharge endin solid strip form. Preferably an intermittent pulling force is appliedto the emerged end of strip 2 I, a symbolic pulling device beingindicated at 39.

As strip 2I passes from the mold, printing edge 20 frictionally contactsthe converging curved portion 22 of upper spacer I5 and as the strip isdrawn therebeyond the printing edge is eifectively burnished by thefrictional engagement with the curved portion.

It will readily be seen that in view of the relatively softcharacteristics of the alloys employed conventionally in type-metal theabove described frictional contact is highly effective to apply aburnish and polish to the printing edge 20 and t0 eliminate therefromirregularitiesy pits or other defects which have frequentlycharacterized printing strips produced by conventional molds. In someinstances it is considered desirable to converge the terminal end ofspacer I5 more abruptly than along the gradual arc of curved portion 22.Under such conditions a more sharply arced portion 22A may be providedadjacent the discharge opening I1. Portion 22A obviously functions inmanner substantially identical to that lalready described in connectionwith portion 22.

It will be understood thatthe foregoing speci- I; cation has describedthe physical aspects of the preferred embodiment of the presentinvention, but that other forms and embodiments thereof may be readilyaccomplished without departing from the scope of :the invention, and itwill, there- To fore, be understood that the present invention is notintended to be limited to the precise embodiment shown, except asdefined in the appended claims.

I claim:

1. In a mold for forming metallic strips which comprises a pair ofsides, a pair of fiat, inwardly facing, side liners, respectivelysupported by said sides, an yupper spacer and a lower spacer, saidspacers extending longitudinally of and being interposed between saidliners to space said liners apart horizontally and being verticallyspaced apart, said liners and the proximate edges of said spacersdefining ,a flat, strip-forming channel, having an entrance end and adischarge end, the said proximate edges diverging from said entrance endthroughout a majority of the length of said spacers, one of said spaceredges remote from said entrance end having a minor portion convergingtoward the other said spacer, the other said spacer edge being straightthroughout its length from end to end of said channel.

2. A device in accordance With claim 1 in which said converging portionis curved along a gradual arc.

3.l A device in raccordance with claim 1 in which 1said upper spacerincludes said converging porion.

4. In a mold for forming metallic strips Which comprises a pair ofsides, a `first spacer, a second spacer spaced from the rst spacer, saidspacers extending longitudinally of and being interposed between saidsides to space said sides apart, said sides and the proximate edges ofsaid spacers dening a fiat, strip-forming channel having an entrance endand a discharge end, one only of said spacer edges remote from saidentrance end and adjacent said discharge end having a minor portionconverging toward the other said spacer, the said other spacer beingstraight throughout its length from end to end of said channel, wherebyto restrict said discharge end with the restriction being located on oneedge only of the discharge end lto burnishingly contact one edge of astrip passing through said discharge end.

5. A device in accordance with claim 4 in which .said minor convergingportion is an arcuately curved portion.

ANTON H. NARROW.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,476,967 Hedly Dec. 11, 19231,567,363 Elrod 1 Dec. 29, 1925 1,567,431 Elrod Dec. 29, 1925 1,946,488Dahl Feb, 13, 1934 2,007,301 Lemieux July 9, 1935 2,131,307 BehrendtSept. 27, 1938 2,135,465 Eldred Nov. 1, 1938 2,187,720 Williams Jan. 23,1940 2,225,373 Goss Dec. 17, 1940 2,310,805 Mueller Feb. 9, 19432,371,604 Brennan -..n Mar. 20, 1945

